Exploring Computer Science (ECS) is a computer science (CS) curriculum designed in response to research findings about the severe limitations of Advanced Placement CS in engaging more than a narrow band of students. ECS is a year-long college-preparatory course, consisting of six units, including problem-solving, Web design, introduction to programming, robotics and data analysis. Designed to introduce students to the foundational, creative, collaborative, interdisciplinary, and problem-solving nature of computer science, ECS is offered in 27 schools in the Los Angeles Unified School District, which is the second largest district in the country. It is also offered in San Jose, Chicago, and Puerto Rico. ECS addresses the injustices of historically denied computer science education to underrepresented populations while also providing students with an engaging yet rigorous experience. ECS teachers are at the core of this effort to increase access to computer science knowledge. They are supported with a professional learning community, in-classroom coaching, and on-going professional development. ECS and Into the Loop, a K–12/university partnership dedicated to increasing equity and access to quality computer science learning in public schools, has been a catalyst and foundation for Mobilize, an NSF CISE and Math Science Partnership-supported project. At the heart of Mobilize is “participatory sensing”—a method of data collection and analysis in which students will use mobile phones and Web services to systematically collect and interpret data about issues important to them and their communities.